(function (doc, win) { 
	var docEl = doc.documentElement, 
	resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize', 
	recalc = function () { 
		var clientWidth = docEl.clientWidth; 
		if (!clientWidth) return; 
		if(clientWidth>=750){ 
			docEl.style.fontSize = '100px'; 
		}else{ 
			docEl.style.fontSize = 100 * (clientWidth / 750) + 'px'; 
		} 
	}; 

	if (!doc.addEventListener) return; 
		win.addEventListener(resizeEvt, recalc, false); 
		doc.addEventListener('DOMContentLoaded', recalc, false); 
	})(document, window); 
